如何在 ElementUI 的表格组件 Table 中插入图片缩略图，通过鼠标悬停显示大图？介绍以下2种方式：

方法1：直接在模板元素中插入

<template>
  <el-table :data="tableData">
    <el-table-column label="图片">
      <template slot-scope="scope">
        <el-popover placement="right" trigger="hover">
          <img :src="scope.row.picture" style="max-width: 500px; max-height: 500px;">
          <img slot="reference" :src="scope.row.thumbnail" style="width: 50px; height: 50px; vertical-align: middle;">
        </el-popover>
      </template>
    </el-table-column>
  </el-table>
</template>

<script>
  export default {
    data() {
      return {
        tableData: [{
          thumbnail: 'https://www.lervor.com/thumbnail.jpg',
          picture: 'https://www.lervor.com/picture.jpg'
        }]
      }
    }
  }
</script>

方法2：通过表格列属性格式化

<template>
  <el-table :data="tableData">
    <el-table-column
      v-for="(column, index) in columns"
      :key="index"
      :label="column.label"
      :formatter="column.formatter"
    />
  </el-table>
</template>

<script>
  export default {
    data() {
      return {
        tableData: [{
          thumbnail: 'https://www.lervor.com/thumbnail.jpg',
          picture: 'https://www.lervor.com/picture.jpg'
        }],
        columns: [
          {
            label: '图片',
            formatter: row => {
              return this.$createElement('el-popover', {
                attrs: {
                  trigger: 'hover',
                  placement: 'right'
                }
              }, [
                this.$createElement('img', {
                  attrs: {
                    style: 'max-width: 500px; max-height: 500px;',
                    src: `${row.picture}`
                  }
                }),
                this.$createElement('img', {
                  attrs: {
                    style: 'width: 50px; height: 50px; vertical-align: middle;',
                    src: `${row.thumbnail}`
                  },
                  slot: 'reference'
                })
              ])
            }
          }
        ]
      }
    }
  }
</script>